diff --git a/plupload.module b/plupload.module
index 6dbbddd..3249bcb 100644
--- a/plupload.module
+++ b/plupload.module
@@ -288,7 +288,7 @@ function plupload_library() {
           'runtimes' => 'html5,flash,html4',
           'url' => url('plupload-handle-uploads', array('query' => array('plupload_token' => drupal_get_token('plupload-handle-uploads')))),
           'max_file_size' => file_upload_max_size() . 'b',
-          'chunk_size' => '1mb',
+          'chunk_size' => parse_size(ini_get('post_max_size')),
           'unique_names' => TRUE,
           'flash_swf_url' => file_create_url($library_path . '/js/plupload.flash.swf'),
           'silverlight_xap_url' => file_create_url($library_path . '/js/plupload.silverlight.xap'),